Automatic focusing device.



L. W. BUTLER.

AUTOMATIC FOCUSING DEVICE.

APPLICATION mu) IAN.25. 1913.

1,142,767. Patented June 8, 1915.

2 SHEE TSSHEET I.

' WITNESSES N1 INVENTOR GJ/{MQMM Louis WBuHem,

ATTORNEYS L. W. BUTLER.

AUTOMATIC FOCUSING DEVICE.

APPLICATION FILED JAN.25, 1913.

Patented June 8, 1915.

2 SHEETS-SHE j] 2.

llllllm INVENTOR W. B u 1 le f,

WITNESSES ATTORNEYS UNITED w. norm or mnw won, it. I.

LUTOHLTIC FOCUSING DEVICE.

imitation of Letton-tatont.

Patented June a, 1 915.

Application filed January as, 1918. amino. 744,140.

To. all whom it may concern:

Be it known that I, LOUIS W. Born, a citizen ofthe United States, and aresident of the cit of New York, borough of Brook- 1 in t e county of Kings and State of l w York, have invented a newand I m proved Automatic Focusing Device, of which. the following is. a full, clear, and exact de scri tion.

hfy invention relates to a device, adapted for use on almost. any kind of rojecting apparatus for the 'sake of ma g enlarged images of given objects. It 'isespecially; diesigned for the purpose of makingfenlargements of negatives and it comprlses essentially a holder for an object whichis to be enlarged, a focusingbgevice, and a "screen on which the object to enlarged is 'focused 'in the well-known way. This screen may be in 4 the form of a holder fora sensitized plate or film on which the enlargement is .to be made.

These parts are mounted so as to be relatively movable, and I employ in conjunctiontherewith a controlling device so constructed that the relative-movements of the parts question are regulatedin such a way that when one of the parts is moved the relative position of one or more of the remaining parts is so changed that-the screenor plate holder always remains'in focusing relation. All the operator has to do, therefore, is to move one'of the parts'the required degree, this depending on the amount of enlargement that is desired. [-1 7 Reference is to be had totheaccompanying drawings forming a part of this specification, in which the same charactersof reference indicate the same parts in all the views. Figure 1 is a vertical longitudinal sectional view of my invention on the line 1- 1 of Fig. 2; Fig. 2 is a horizontal sectional view on the line 22 of Fig. 1; Fig. 3 is a top plan of part of the controlling'mecha nism; Fig. 4 is a bottom plan of the same;

Fig. 5 is a sectional view on the line 55 of Fig. 3; Fig. 6 is a sectional view on the line 66 of Fig. 3; and Fi 7 is a diagrammatic view showing the s ape of part of the controlling mechanism. y i My invention comprises -a base 1 which may be thebase of any kind of projecting or photographing apparatus, and on this base'l mount an object holder 2 and a. lens-"holder 3 carrying a suitable number of lenses in-' closed in a casing d. This lens holder is lo or film on which the enlargement is to be made; In the form shown in the drawings the screen 5 is fixed, but the base is provided with rails or guides 6 on which the lens holder and the vobject holder are movably mounted so that the distance of these two parts from each other and from themember 5 can be increased or decreased at will.

I control the movements of thehbj' g. lder andthe lensholder 3 by me mechanism which is normally located between these arts and fixed with reference-H to the lens ho der by means of a bar or other" convenient form of support on which the controlling deviceis carried. This controlling 'devicecomprises essentially a plate 8 in which is formed'a spiral-cam slot and the plate 8 is provided with a hub byimeans ofwhich it is fixed upon a spindle-1'0; This spindle 10 is mounted in bearings formed in" plates 11 which are secured together by suitable bolts but are held asuitabl'e distance apart by means of spacing sleeves 12 surrounding these bolts and located between the'plates. The plate 8 will be located near the bottom plate, and secured to the shaft 10 just below the upper plate is a gear wheel'13. This gear wheel 13 is engaged by a-pinion 14 on a spindle 15 having a bearing in the up per plate and projecting above this plate and carrying on its upper end another pinion 16 which engages a rack 17. This rack 17 is fixed to the base 1.

The above parts are carried on the bar 7 by providing this ,bar with arms or projections and fastening the same to. the upper plate 11. Of course any other convenient method of attaching the framecomprising the plates 11 to the-lens holder 3 may be em ployed. I-

The cam slot 9 actuates a stud'or bolt 18 having an anti-friction sleeve 19'at its upper end and carrying on its lower end a pinion 203- This pinion 20 actuates arack bar 21 secured to the obi'ect holder 2and mounted to slide in suitable openings carried by the with the fixed rack 23, and transmit a greater degree of movement to the movable rack 21. This fixed rack 23 and pinion 20 constitute in effect a multiplying arrangement, and I prefer to mount this pinion on a sliding plate 25 which serves as a support therefor.

The rack 23 is secured to the lower plate 11 by means of suitable spacing devices 24, these spacing devices comprising a pair of plates which extend crosswise of the lower face of the lower plate 11 and are recessed to receive the plate 25 in which the stud 18 is carried. They also include Fig. 5 a plate 25' which extends longitudinally from one of the cross-pieces 24 to the other, thus forming a sort of guideway in which the plate 25 moves. This plate 25 will normally move about one-half of the distance traveled by the rack bar 21 whenever the cam actuates the pinion 20. The rack 23 may be provided with lugs 26 which are slotted. and it may be secured to the lower plate 11 by means of screws 27. These slotted lugs permit the adjustment of the rack 23 toward and from the rack 21.

Any suitable arrangement for inclosing the lens casing 4 and providing a dark chamber into which rays of light pass to be focused on the sensitized plate carried by the screen 5 may be employed. I show ordinary folds of cloth 28 on Fig. 1 for this purpose.

In order to proiect an enlarged image of an object mounted in the holder 2, it is only necessary to slide the lens holder 3 back and forth along the rail 6. Through the racks and pinions above described motion will be transmitted to the holder 2, and this motion will, because of the shape of the cam slot 9, be just enough to keep the parts in all positions in correct focusing relation with re spect to the fixed screen 5.

The shape of the slot 9 in plate 8 is plotted in Fig. 7 and shown in detail in Figs. 3 and 4, the same acting as a cam on the spindle 19, whereby the focusing may be controlled so as to enlarge an image to several times the size of the object. The shape of this slot must of course be proportioned in accordance with the size of the various gears and pinions hereinafter fully described so that the lens and the obiect will be moved toward or from each other for continually maintaining the object in focus. Arranged on the slot as shown in Fig. 7 are a plurality of points designated as a, b, c, d, e, f, g, k and 2', these being arranged on the slot as a matter of convenience for indicating when the enlargement has reached a certain size. For instance, a double size or triple size. These distances may be secured by any suitable means, as, for instance, by a mathematical calculation or by plotting the same directly upon the cam, the particular method of securing these distances not forming'any part of the present invention. If the stud 18 be located at the point a and the cam then turned so as to bring the slot into such position that the stud will be located at the point b, the size of the object or negative will be doubled. If further movement is effected so as to bring the slot into such position that the stud 18 will be located at the point a, the negative will be enlarged three times and so on up to the point i, where it will be enlarged nine times.

Of course I may employ my invention for making images of any obiect, as it is by no means restricted to the enlargement of negatives. Instead, almost anything that is to be projected might be located in the holder 2.

As stated above, I am enabled to control the focusing for an enlarged image up to nine times the size of the object. and by increasing the dimensions of the cam I can control the focusing so as to produce an enlargement of a given obiect up to any number of times the size thereof. The movement of the lens to or from the screen one focal length will cause a movement of the object holder which movement will be in proper proportion to the movement of the lens. Suitable multiplving gears and cams are provided for causing a proper movement of the object holder in relation to the lens for maintaining the object holder a proper distance from the lens at all times for presenting a proper focus.

It will be seen that when the controlling 100 device moves with the lens holder 3 the pinion 16 is turned by the fixed rack 17, and it will be readily understood that the resultant movement of the rack 21 and the object holder 2 will be due both to the cam slot and 105 the bodily movement of the disk in which the cam slot is formed. It is of course to be understood that the rack 17 will be made as long as is required to produce the desired results. 'It may extend the full length 110 of the base 1 if required.

When it is desired to' change from a copying factor of one, the lens holder is moved away from the screen one inch, and this movement causes the various gears hereto- 115 fore described, together with the cam, to transmit motion to the object holder for causing the same to move a proper distance for maintaining the object therein properly in focus. This distance is one half an 120 inch to the right as the parts are arranged in Fig. 2 of the drawings, whereby the lens will be three inches from the screen and the object holder four and one half inches from the screen. As the lens has moved away from the screen 5, the same carries all of the gear wheels heretofore mentioned and in this movement causes the pinion 16 to rotate. This rotation is sufiicient for transmitting a proper movement to the cam 8 for causing the cam to move one eighth of a revolution, such movement of the cani being in a counter-clockwise direction, whereby the object holder is moved one half of an inch to the left by the cam while the entire structure is being moved one inch to the right, thus resultin in a one half inch advance of the object older. If the cam 8 were stationary, the pinion 20 would not rotate and consequently the object holder would be moved the same distance as the lens, but by reason of the counter-clockwise rotation of the cam when the lens is moved to the right, the object holder is given a reverse movement according to t e shape of the cam which, in a change from a copying factor of one to a copying factor of two, is one half inch with the particular lens described. The shape of the slot of the cam from b to a (Fig. 7) is such as to maintain the proper distance between the lens and the ob ect holder for maintaining the focus at all points so that the device can be moved so as to have a copying factor of one, two or more, or a copying factor of, for instance, one and one half or any other fraction desired.

I desire to have it understood that the above description is illustrative only and I' do not care to be limited to the exact arrangement or details shown and described, but reserve to m self the right to make such changes in the ape, size and arrangement of the parts as fairly fall within the scope and spirit of my invention.v

Having thus described my invention, I

claim as new anddesire to secure by Let-' ters Patent:

1. The combination of a screen, a lens holder and an object holder, guides on which the lens holder and the object holder can be from the screen, a fixed rack, a rack connected to the object holder, and means carried by the lens holder and engaging said racks to control the movements of the lens holder and object holder to keep the screen always in focusing relation.

2. The combination of a' screen, a lens holder and an object holder, means for mounting the object holder and the lens holder so that the same can be moved ward and from the screen, a fixed rack, a

rack connected to the ob'ect holder, a pmion, and a cam actuated t ereby to transmit relative movement to-the rack connected to the object holder, said cam and said pinion being carried by the lens holder, said pinion meshing with said fixed rack, said cam being shaped to cause the lens holder and the object holder to be moved to such an extent with respect to each other as to keep the screen always in focusing relation.

3. The combination of a screen, a lens holder, an object holder, means for mounting the lens holder and object holder to be moved toward and from the screen, a fixed rack, a pinion and a cam actuated thereby, said pinion and said cam being carried by the lens holder, said pinion beingJ actuated by said fixed rack, a rack carried y the object holder, and a. multiplying device between said cam and said second-named rack, said cam being sha' ed so as to cause the movement of the obJect holder with respect to the movement of the lens holder when the latter is moved to keep the screen always in focusing relation.

4. The combination of a screen, a lens holder, an object holder, means for mounting said object holder and lens holder in position to be moved toward and from the screen, a fixed rack, a rack connected to the object holder, a pinion, means actuated by said fixed rack for rotating said pinion, a gear wheel actuated by said pinion and a slotted cam actuated by said gear wheel, said.pinion, ear and cam being carried by the lens hol er, a spindle actuated by the cam, a pinion on said spindle, said spindle and said pinion thereon also being carried by the lens holder, a rack meshing with said last mentioned pinion carried by said lens holder for causing a rotation of said pinion when the lens holder is moved, the firstnamed. pinion en aging and receiving movement from the xed rack for rotatin said ar wheel, the said slotted cam eing apd to cause the ob'ect holder to be so moved with respect to e lens holder when the lens holder is moved, as to keep the screen always in focusing relation.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

LOUIS W. BUTLER.

Witnesses: 

